Self-adjustable contact-maker for electric switches.



F. W. YOUNG. I SELF ADJUSTABLE CONTACT MAKER FOR ELECTRIC SWITCHES.APPLICATION FILED DEC. 26. 1905.

1,001,796. Patented Aug.29, 1911.

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nae/ma w: round, or EVERETT, MASSACHUSETTS, ASSIGNOR TO SEARS B.CONDI'I, JR. or BOSTON, MASSACHUSETTS.

SELF ADJUSTABLE CONTACT-MAKER FOR ELECTRIC S WIT CHESL earner.

Specification of Letters Patent. Patented Aug. 29, 1911,

Application filed December 26, 1905. Serial No. 293,248.

following description, in connection with the accompanying drawings, isa specificatron, lik'e; letters on the drawings representing like parts.

My invention relates to electric switches,

being herein shown as applied to the automat c ClI'CUlCblEZlkBl type ofswitch; and

has for its object the provision of means for maintaining perfectseating of the switchcontact upon the contact blocks in that type ofswitch havnig a bridge-contact member.

The constructional details of 'my invention will be fully eirplained inthe course or V the following detailed description, refer-' ence beinghad to the accompanying drawings, in which I have shown a preferredembodiment of .my invention.

. ,In' the drawings, Figure 1 represents in side elevation a circuitbreaker having my invention applied thereto. FLlgS.-2, 3 and 4 areenlarged broken details showing my improvementin top plan, longitudinaland transverse'sectmn; the latter figuresibeing "taken on the dottedlines 3 3 and i e,

Fig.2,respectively Both -troi i" the inanu'facturers standpoint and.the' uscrsstandpoint, consid- .terrible,-ditlicultyhasv been commonlyeX- perienced --1n securing and maintaining "proper alinernent of theswitch contact with" the stationary contactblocks in abridge-contactswitch? For instance, if the castings were slightly out of true, it hasbeenconimo'nly necessary toreadjust all the ijointsjand pivots,trueup.thefvarious hearing surfaces, and otherwise waste time andmoneyin adjusting each individual circuit breaker-, in'order to bring thesliding contact of the ends of; the laminated brush into flat rubbingpressure with the contact blocks. Also, in use,-'it the contact surface"of the brushbecomes burned or otherwise roughened or injured, it'- isnecessaryto file it off so as to maintain the flat-rubl' 1ngcontact'above mentioned. and this has usually necessitated .a I carefuladjustn'icnt of the pressurebytighteni-ng or loosening certain screws,alarms necessitated repeated testthat the back ing and experiments toinsure that the sure is even on bothends of the brush, 1

My invention -aims to provide means for fitting the brushes once forall, so that there is no necessity for fitting each individual circuitbreaker in the laborious. manner above e plained', at the factory, andalso I have-eliminated the laborious and skilled adjustment in use.

Referringto Fig. 1, it will be understood plate 1, upper and lowercontact blocks 2, auxiliary carbon contact 3, binding posts 4, trip'5,armature core 6, and armature inclosure ,7, may be ofany well known orpreferred kind, as also the general features of this switch, which is,herein shownas comprising a handle 8 pivoted at 9 and connected by atoggle link 10 to a switch-arm or leverll, which carries atits pres-'free end a bridge-contact l2 and auxiliary contact 13.

Referring now to Figs-2, 3 and 4, it will be seen that the laminatedcontact 12 is clamped between a back plate '14: and front plate 15,having complementary angular surfaces for maintaining the lamina: ofthey bridge 12 in proper position and all secured together by a bolt 16and nut 17 on the threaded end there'ot..-Above the back plate 14.1provide a chambered cap or supporting barrel 18, pivoted on oppositetrunnions or pivots 19 and carrying a plurality. of comparatively heavysprings 20, preferably of considerable length, as shown in Fig. 3, andretained separated in the .in-

terior of the cap 18, as by means of pockets 21, as herein shown. In thetype of switch herein explained," I have shown four of these springsarranged to get a proper counterbalancing etiect, as shown in Fig. 2,and .in pairs at the opposite sides of the longitudinal center andalsoin pairs-at the opposite sides of the transverse center of V thebridge and its supporting parts. In larger types of switch I employ sixor more springs, while in smaller ones I employ one or more o'nly. orother forms or kinds of yielding member, such as rubber. for instance.These springs 20 bear forcibly uponthe top surface ofthe back plated/l,the adjacent edges of the back plate and cap being cut awayorshouldered. as indicated at 22 23, to permit limited yielding movementfreely'in any direction; A pin 24;, or any other suitable means, may beprovided 2 memes for preventing=relative rotation of the parts on thefboltiiltij and a pin 25 is provided to limit the swingingmovcment ofthe bridge on its Epivots19.

5 It will be understood that the yielding arrangement and constructionwill be varied to suit the various types of switches and circuitbreakers, and that various modificationsgthei'eof' maygbe made withoutdeparting from the spirit and scope of my invention as defined in theclaims and explained in t-hedescription,

The practicalside of my invention will be at once seen? 'Iftthecontacting surfaces of the bridge 12 become'iniured or for other reasonsare fileddown, all that is necessary is to slightly slacken the bolt 16in order to restore the bridgejtoits original distance from theswitch-arm 11, unless the bolt is 2 left always in slack' adjustment,which is often preferable, inasmuch as the yielding construct-ionprovided my the springs 20 will tend automatically to giving therequired even pressure fontlie oppositeends of said bridge; Theserrnc'lsi or legs of'the bridge or A- 'shaped contact have their engagingsurfaces oblique tothe'general direction of their length, Thisleliminates entirely the necessity of repeated k xperiment and carefuladjustment of pressure screws and other devices which haveheretoforebeen commonly employed rcr bringing the'correct even pressureupon the opposite ends of the bridge. It also, does away with thenecessity for the extreme accuracy. of filingdown the opposite endslofthe brush; which has heretofore been necessaryfifln other words, itrenders the bridge vcontact"of the circuit breaker largely 'alutomaticand self-adjusting. Also 40 from the manufacturing standpoint myinvention' is even more advantageous. The bridge .fpieces may all bemade alike and imply clamped between the holding plates n usual manner,and then the parts assem- '.-bled, whereupon all minor difierences orinaccuracy in the arm, casting 11 and the various pivots andtconnectionsthereof, will not materially aifectft-he accuracy of the bridge inasmuchas the springs will permit '50 the latter. to aline properly andaccurately with theacontactvblocks. This does away with the expensive,and laborious fitting of,

each individual circuit breaker, heretofore necessary.

.55 Having described my invention, what I claim as new, and desire tosecure by Letters Patent,is;

1L In an electric switch, separated contact blocks, va mo 'able contactelement for spanninp' samje,-a, movable carrier for operating saiomovable contact element, and a backing support pivotedto said movablecarrier affording aseatfor, said movable contact element, said backingsupporthavihg pro- 5 vision to permit yielding of'said movable sistanceto angular displ-acen contact element relative thereto in alldirections:

2. In a electric switch, separated fixed contacts, a movable spanningcontact element, a movable carrier therefor, a pivotedgt) connection topermit said movable contact" element to swing transversely in its planeof operative movement and another, connectionpermitting said movablecontact element to yield bodily and angularly in all directions relativeto said carrier.

3. In an electric switch, separated fixed cont-acts, a-movable spanningcontact 'element, acarrier therefor mounted for movement bodily towardand from said fixed contacts, and interfitting connections between saidmovable co'ntact'element and said carrier formed to permit' relativebodily yielding in the direction of its movement and self adjustmentangularly in all directions between said parts, said interfitt-ingconnections including strongly resilient means acting uponsubstar'itialareas of the interfitting portions and offering substantial resistanceto relative angular displacement of said members 4. In an electricswitch, separated contact blocks, a movable bridge-contact for spanningthe same, a. supporting arm for operating said bridge-contact, aspring-supporting device separate from the bridge-contact, pivoted 1nsald arm, spr1ngs carried thereby,

and means carried by said bridge-contactin engagement with said springsand mov'ably connected to said separate supporting device, cooperatingwith said springs and device in automatically al'ining said bridge withthe contact blocks as the supporting arm carries the bridge-contact intoclosed position, v

5. In an electric switch, separated fixed. contacts, a movablebridge-contact for spanning the same, a. supporting arm for operatingsaid bridge-contact, a cap 'pivoted to said arm forming a seat for saidmovable bridge-contact and springs housed in said cap disposed to act atSeparated points upon said bridge-contact to offe 'si'l'bstantia-l re-'I t thereof.

6. In anelectric switch, separated contact blocks in the planeof ovementof the bridge-contact, a. movab e' arched bridgecontact for spanning thesame having its projecting ends provided with engaging sur- 7 facesoblique to the general direction of their length, a supporting armforoperating said bridge-contact, a spring-supporting device separatefrom the bridge-contact pivoted in said arm, springs carried thereby,and means carried by said bridge in engagementiwith said springs andmovably connected Ito-said ioo supporting device, cooperating-"with'said 1 springs and device in automatically ali ning said oblique endswith the c act-blocks,

blocks, a movable bridge contact for spanning the same, a supporting armfor operating said bridge contact, a cap transversely pivoted in saidarm, means movably connecting said bridge withsaid cap, and yieldingmeans retained by said cap in pressing engagenient against said bridgefor equalizing b the pressure of the latter.

8. In an electric switch, separated fixed contact blocks, abridge-contact for spanning the same, a carrying lever therefor, achambered cap pivoted transversely in said carrying lever, yieldingmeans carried within said cap, and means retaining said bridgecontact inmovable engagement with said yielding means.

. 9. In an electric switch, separated fixed contact blocks, a bridcontact forspanning the,same, a carrying. lever therefor, a chamber dcap ridge-con act centrally to said cap in yielding engag cut with said"springs.

In testimony whereof, I have signed my 25 name to th specification, inthe presence of two subscribing witnesses.

' FRANZ W. YOUNG.

in oppositEiairs, and means connecting said Witnesses:

. GEO. H. MAXWELL,

ELLA. Jones.

pivoted transversely in said 20 I carrying ever, springs-mounted 1n saidcap

